The Flow Cytometry Core has been established during the past year at the Columbia Diabetes Research Center. In the past funding cycle, there has been substantial growth in requests for flow cytometry services to assist diabetes investigators. The interest has been catalyzed by several initiatives to study pathogenesis and treatment of Type 1 Diabetes, including the new NIDDK-funded Epigenetics Program, the creation ofthe Columbia Center for Translational Immunology, and Genetics of autoimmunity initiative. In addition, the ability to isolate genetically modified rare cell populations from organs like brain, endocrine pancreas, adipose tissue, and gut has become critical to the research of DRC faculty. The DRC Flow Core was established in 2011 with substantial institutional as well as NIH support in the form of a Shared Instrumentation Grant. It was fully integrated within the DRC during the past year to meet the growing need ofthe DRC User base for flow cytometry, as demonstrated by 17 users supported by 33 grants, who have already obtained 5 new grants. The Core has already supported 16 publications as primary Core. User projections demonstrate a growing demand for these services, with 37 declared users for the coming year. The expertly staffed Flow Core is situated in renovated Department of Medicine space and houses four, state-of-the-art BD flow cytometers, including a 6-laser LSR II and a 4-laser BD Influx sorter. There is strong demand for these high-quality services. In particular, the BD Influx is only the second biosafety level-2 sorter available campus-wide for human cell sorting. More than 90% ofthe current use is by DRC faculty, a substantial portion of which are new NIH-funded Investigators recruited to CUMC in the previous funded period (Sykes, Farber, Yang). The Core Director Dr. Clynes is thoroughly integrated within the DRC and the Columbia biomedical community, and its Technical Director Dr. Siu Hong Ho is a superb operator and immunologist, enabling this Core to be a vibrant collaborative center of excellence.